This application requests continued funding for an Animal Resource Laboratory based in the Section of Comparative Medicine, Yale University School of Medicine. The proposal has 2 major objectives: 1) to continue research on diseases of laboratory animals that interfere with animal- related research and that have potential as animal models and 2) to continue partial support of diagnostic laboratories that service the veterinary care program and the laboratory animal medicine training program. Studies of infectious diseases, particularly viral diseases, have been a major interest of this Resource Laboratory and will remain the focus of the proposed research. A significant benefit of the work will be continued improvement and refinement of diagnostic methods and reagents vital to quality veterinary care at Yale and to enhance laboratory animal medicine nationally. Many of the pilot projects have potential for future funding as individual research grants. These include: effects of viral infections on aged and immunodeficient mice, the pathogenesis of picornaviral and parvoviral infections of mice, the pathogenesis of B virus in monkeys, in vitro characterization of rat coronaviruses, and animal models of human papillomatosis and osteoporosis. Applied research leading to development of nucleic acid probes for rapid diagnosis of murine viral infection, embryo transplantation methods for rederiving virus infected mice and the diagnosis and treatment of simian endometriosis is also proposed. Many methods are required for these projects and range from routine histopathology to recombinant DNA technology.